Effect of dietary nutrient supplementation on birth outcomes in pregnant women with gestational diabetes mellitus: A network metaanalysis.

BACKGROUND

Gestational diabetes mellitus (GDM) adversely impacts maternal and fetal health. This study analyzed the effects of dietary supplements on birth outcomes in GDM pregnancies and offspring.

METHODS

PubMed, Embase, Cochrane, and Web of Science were searched until August 30, 2024, and the search was updated on January 10, 2026. Cochrane's risk of bias tool assessed study quality; Stata17 performed analyses.

RESULTS

A total of 11 randomized controlled trials (RCTs) were included, with 1431 pregnant women with GDM. Probiotics significantly reduced the incidence of macrosomia compared to placebos (risk ratio [RR] = 5.98, 95% credible interval [CrI][1.11, 43.42]). No other significant differences were found for primary outcomes. Surface under the cumulative ranking curve (SUCRA) probabilities indicated that synbiotic was ranked best for reducing cesarean delivery (SUCRA = 78.20%), and probiotic plus vitamin D was best for lowering preeclampsia risk (SUCRA = 78.64%). In newborns, ω3 was best for reducing preterm birth (SUCRA = 72.08%), high-dose vitamin D for increasing birth length (SUCRA = 87.15%), probiotic plus vitamin D for increasing head circumference (SUCRA = 84.08%) and reducing macrosomia (SUCRA = 78.92%), and L-ascorbic acid for lowering neonatal hypoglycemia (SUCRA = 98.99%).

CONCLUSION

No single intervention had a significant effect on all outcomes in both mothers and newborns. Notable among the interventions were vitamin D and its combination with other dietary supplements, especially probiotic plus vitamin D. Further confirmation is expected from larger-sample multicenter RCTs in the future.